A boat can travel 80 km downstream in 8 hours. If the speed of the current is 4 km/h, what is the speed of the boat in still water?
Practice Questions
1 question
Q1
A boat can travel 80 km downstream in 8 hours. If the speed of the current is 4 km/h, what is the speed of the boat in still water?
8 km/h
10 km/h
12 km/h
14 km/h
Speed downstream = Distance/Time = 80 km / 8 h = 10 km/h. Speed of boat in still water = Speed downstream - Speed of current = 10 km/h - 4 km/h = 6 km/h.
Questions & Step-by-step Solutions
1 item
Q
Q: A boat can travel 80 km downstream in 8 hours. If the speed of the current is 4 km/h, what is the speed of the boat in still water?
Solution: Speed downstream = Distance/Time = 80 km / 8 h = 10 km/h. Speed of boat in still water = Speed downstream - Speed of current = 10 km/h - 4 km/h = 6 km/h.
Steps: 9
Step 1: Understand that the boat travels downstream, which means it is helped by the current.
Step 2: Calculate the speed of the boat downstream using the formula: Speed = Distance / Time.
Step 3: Plug in the values: Distance is 80 km and Time is 8 hours. So, Speed downstream = 80 km / 8 h.
Step 4: Perform the calculation: 80 km / 8 h = 10 km/h. This is the speed of the boat when going downstream.
Step 5: Know that the speed of the current is given as 4 km/h.
Step 6: To find the speed of the boat in still water, subtract the speed of the current from the speed downstream.
Step 7: Use the formula: Speed of boat in still water = Speed downstream - Speed of current.
Step 8: Plug in the values: Speed of boat in still water = 10 km/h - 4 km/h.
Step 9: Perform the calculation: 10 km/h - 4 km/h = 6 km/h. This is the speed of the boat in still water.
